jfox78 Posted December 15, 2015 Share Posted December 15, 2015 Hey guys, I have an issue maybe someone can shed some light on.... Here is what my obs is doing- With the shifter in "D", launches on any loose or slick surface results in front wheels spinning for maybe 1 or two revolutions, then the rear kicks in with a harsh thud. Shifter in 1 or reverse results in no wheel spin and instant awd goodness. Shifter in 2 results in something in between the other two (quicker awd, but still delayed). So what's up here? Is my duty c getting slow with age? 184k on the clock. Would a fluid change help? Fluid is pretty icky. Not burnt, but really not pink and funky like it should be. Any help would be awesome! Thanks! Quote Link to comment Share on other sites More sharing options...
jfox78 Posted December 15, 2015 Author Share Posted December 15, 2015 Another thought.....could the vehicle speed sensors have anything to do with this? I know they're one input to the tcu telling it that the fronts are slipping. I dunno. I'm.about ready to wire up a switch to the duty c for the snow this winter! Having delayed awd is almost worse than not.having it! When the rear kicks in, it sends you sideways when you don't want it to!! Lol! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 15, 2015 Share Posted December 15, 2015 Change the old fluid first. If it has the spin-on filter change that as well. 1 Quote Link to comment Share on other sites More sharing options...
mikaleda Posted December 15, 2015 Share Posted December 15, 2015 Change the old fluid first. If it has the spin-on filter change that as well. Best place to start, new fluid can do wonders Quote Link to comment Share on other sites More sharing options...
AdventureSubaru Posted December 15, 2015 Share Posted December 15, 2015 x3 to start with fresh fluid. If it's dirty, this can only help. 3 drain and fills with some driving in between each gets you almost 100% new fluid. And clarify "launches" - is this under normal acceleration? Or if you're thrashing this car you're just asking for problems to get worse. My wife's old 2000 Outback with 350,000 miles would tend to thud and jump a bit in snowy or slippery roads. Seems they often thud around a bit when they lose traction. See where you're at with new fluids. Quote Link to comment Share on other sites More sharing options...
jfox78 Posted December 16, 2015 Author Share Posted December 16, 2015 (edited) Yeah, I'm not thrashing at all, lol. Just normal acceleration from a stop. I'll have to try fresh fluid and see where that gets me. I still may run a switch to the duty c though. I like the idea of a locked (so to speak) center diff for slippery situations. Btw...has anyone ever tried autozones trans filter for our cars? Or is OEM a better bet? I know non OEM stuff can be made a.little differently internally. Thanks! Edited December 16, 2015 by jfox78 Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted December 16, 2015 Share Posted December 16, 2015 Below 30mph or so it will look at the front speed vs back to help make torque transfer decisions. In 1 it does apply a little more torque to the rear by default. What happens when you gas it a bit before removing your foot from the brake? What happens if you go to '1' then back to 'D' then take off? I could see sticky plates or a grooved clutch basket causing a short delay that maybe going into '1' 'fixes' (plates do what they should before power applied) If it's all working properly locking the clutches doesn't really buy anything, with the added problem that going down slick hills the rear will slide out as front braking force gets transferred to the rear wheels. External filter- you definitely want to use the subaru. Quote Link to comment Share on other sites More sharing options...
mikaleda Posted December 16, 2015 Share Posted December 16, 2015 Ya its definatly a good idea to use OEM trans filter IMHO Quote Link to comment Share on other sites More sharing options...
jfox78 Posted December 16, 2015 Author Share Posted December 16, 2015 I'll have to try putting it in 1 first and see if that "presets" the transfer clutches. On an unrelated topic, would it be possible to trick the trans to thinking the shifter is in 1 when its actually in d? (transfer clutch wise) Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted December 16, 2015 Share Posted December 16, 2015 Can't think of an easy way. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 17, 2015 Share Posted December 17, 2015 Nope. You tell the trans its in 1 and it stays in 1 all the time. When the duty C and transfer clutches are functioning properly the engagement is flawless, you won't even notice it. If the fluid change doesn't help, probably need to replace the transfer clutches. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted December 17, 2015 Share Posted December 17, 2015 (edited) +1 change fluid. changing the filter is a waste of time IMO. maybe if you separate the rear extension housing to replace clutches, then do it but pointless now. they're closed systems not subject to contamination. 200,000 mile transmissions have spotless internal screens and the external spin on filters last the life of the vehicle per Subaru recommendations. though it would make sense to replace it at some point - i just wouldn't do yours until youre done troubleshooting as it's nto the cause of your issues. Edited December 17, 2015 by grossgary Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted December 17, 2015 Share Posted December 17, 2015 If the fluid is old, wrong, or water contaminated it could cause the plates to be 'grabby' instead of increasing friction smoothly, happens on motorcycle oil-bath clutches on occasion. It is a bit of an outside chance, but at least relatively easy to try. Quote Link to comment Share on other sites More sharing options...
jmoss5723 Posted December 17, 2015 Share Posted December 17, 2015 Your car is working exactly how it should, maybe a little rough, though. The auto trans in your car does not evenly split power to all 4 wheels. In D, the default split front/rear before any wheel spin is like 90/10 or 80/20. In 1, it is 60/40. The "harsh thud" is after the AWD system compensates for the wheel spin by transferring more power to the rear. Ideally, there is no harsh thud, but the power transfers you're describing are right on. Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted December 18, 2015 Share Posted December 18, 2015 I'm having the same issues with the wife's '99 Forester. Once the front wheels slip, there is a noticeable delay in the rear-drive engagement. The fronts spin for a half-second or so, then BAM! AWD engages. It's bad enough that it once nearly caused me to lose control of the car. I spoke with a service manager at Chaplin's about it and apparently in '00+ there is a different rear-drive clutch computer that has a more gradual AWD engagement vs the abrupt nature of the '99's computer. I think that might be part of the story, but, there is a good chance the duty-C solenoid may need to be replaced. The ATF in her car isn't new, but it doesn't have a ton of miles on it. Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted December 18, 2015 Share Posted December 18, 2015 It isn't clear to me there'd be a solenoid fault that would lead to delayed/harsh engagement. Now a sticky shuttle valve (the actual valve that does the sending of fluid to the clutch), that would do it. I don't think anyone has seen this happen, though. Quote Link to comment Share on other sites More sharing options...
mikaleda Posted December 18, 2015 Share Posted December 18, 2015 No matter what a fluid change would be the logical first step in diagnosis. Quote Link to comment Share on other sites More sharing options...
jfox78 Posted December 20, 2015 Author Share Posted December 20, 2015 (edited) UPDATE- So, I drained and filled the trans today. Fluid that came out wasn't burnt, but was dark and thin. No grit or particulates were noticed in the draining fluid, or on my arm since it got soaked in the process, lol. Filled it up, and took it for a drive. Immediately noticed smoother and firmer shifting, and the time it took for drive to engage from park went from about 3 seconds to 1 second. AWD delayed engagement is GONE!!! Totally seamless now! I even pulled into mud and stopped uphill on a steep grass bank. Hit the gas and just took off, four wheels spinning, like it wasn't even an issue! Whether the shifter is in 1 or Drive its now exactly the same taking off. The "thud" of the rear wheels kicking in is gone! Thanks so much everyone! I never would have thought that fluid could have caused those issues. Now I'm looking forward to snow! Over the next two weeks, I'll drain and fill it two more times as suggested by you fine folks. Edited December 20, 2015 by jfox78 1 Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 21, 2015 Share Posted December 21, 2015 Auto trans fluid loses its friction characteristics as it gets old due to the additives in the fluid breaking down. New fluid makes a big difference. Quote Link to comment Share on other sites More sharing options...
jfox78 Posted January 12, 2016 Author Share Posted January 12, 2016 Just an update.... We got our first snow today, and let me tell you, what a difference!! Car before was all kinds of squirrely and would push around corners and was generally sucky in the snow on the highway. With the awd functioning correctly its like I'm velcroed to the road! Predictable in every way, no front wheel spin up and rear bang, and just plain goes!! Thanks Subaru! Lol Quote Link to comment Share on other sites More sharing options...
CNY_Dave Posted January 12, 2016 Share Posted January 12, 2016 Excellent! Quote Link to comment Share on other sites More sharing options...
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